/*********************************************************************************/
/*                        Made By K.N (eu8198@hanmail.net)                       */
/*Algorythm; input month tab of year 2000, and plus 1 if the ycounter is not 윤년*/
/*           and plus 2 if the ycounter is 윤년.                                 */
/*********************************************************************************/
#include<iostream.h>
#include<stdlib.h>
#include<conio.h>
// Array                                                                // 배열 공간
int        month_days[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; // 요일 수
int month_tap_2000[] = {0 ,6 ,2 ,3 ,6 ,1 ,4 ,6 ,2 ,5 ,0 ,3 ,5};         // 2000년의 빈공간 수
// Function                                                             // 함수 공간
void namemonth();                                                       // 달의 이름출력
void monthtab();                                                        // 그 달의 공간계산
//void print();                                                                                                                        // 출력하는 함수
// integer                                                                                                                                // 정수변수 공간
int y, m, c;                                                            // year,month,counter의 약자
int plusc;                                                                                                                                // 그 달의 공간만큼 c에 플러스
char a;
void main(void)
{        
        cout << "Calender Program. Made by K.N\nIf you found some bugs, send e-mail to eu8198@sayclub.com"<<endl;
        while(1){
                y = 0; m = 0; c = 0;
                cout << "  Input year  : ";
                cin >> y;
                cout << "  Input month : ";
                cin >> m;
                if((y%4)==0)                                                                // 윤년 계산
                {
                        if((y%100)==0)
                        {
                                if((y%400)==0)
                                        month_days[2]=29;
                        }
                        else  month_days[2] = 29;
                }
                system("cls");                                                                // 입력부분 삭제
                if(y<0)
                        cout << "     BC "<<-y << " year  ";
                else
                cout <<"     " << y << " year  ";
                namemonth();                                                                // 1 ->  January .. 이런식으로 바꿔주는 함수
                cout << "Sun Mon Tue Wed Thu Fri Sat"<<endl;
                monthtab();
                c = c+plusc;
                
                for(int i=1;i<=month_days[m];i++)
                {
                        if(i<10)cout << " ";                                        // 자릿수 맞추기
                        cout <<i << "  ";                                                // 일정공간 띄우기
                        c++;
                        if(c%7==0)cout << "\n";                                        // 7로 나눠서 줄맞추기
                }
                cout << "\n";
                cout << "Do you want to continue?[Y/N] : ";
                cin >> a;
                if(a == 'n' || a == 'N'){
                        system("cls");
                        cout << "Thank you for using it.^-^"<<endl;
                        exit(1);
                }
                else system("cls");
        }
}
void namemonth()
{
        switch(m)
        {
        case 1:cout << "January"<<endl; break;
        case 2:cout << "February"<<endl; break;
        case 3:cout << "March"<<endl; break;
        case 4:cout << "April"<<endl; break;
        case 5:cout << "May"<<endl; break;
        case 6:cout << "June"<<endl; break;
        case 7:cout << "July"<<endl; break;
        case 8:cout << "August"<<endl; break;
        case 9:cout << "September"<<endl; break;
        case 10:cout << "October"<<endl; break;
        case 11:cout << "November"<<endl; break;
        case 12:cout << "December"<<endl; break;
        default: cout << "error! Try again!!"; exit(1);
        }
}
void monthtab()
{
        int iy;
        iy = 2000;
        plusc = month_tap_2000[m];
        if(y>2000)
        {
                while(iy != y){
                                iy++;
                        if((iy%4)==0)
                        {
                                if((iy%100)==0)
                                {
                                        if((iy%400)==0)
                                                plusc+=2;
                                        else
                                                plusc+=1;
                                }
                                else
                                        plusc+=2;
                        }
                        else
                                plusc+=1;
                }
        }
        else if(y == 2000){;}
        else if(y<2000)
        {
                while(iy != y){
                        iy--;
                        if((iy%4)==0)
                        {
                                if((iy%100)==0)
                                {
                                        if((iy%400)==0)
                                                plusc-=2;
                                        else
                                                plusc-=1;
                                }
                                else
                                        plusc-=2;
                        }
                        else
                                plusc-=1;
                        
                }
        }
        if(plusc>=7 || plusc<=-7) plusc%=7;
        if(plusc<0)
        {
                plusc += 7;
        }
        for(int i = 0;i < plusc; i++)
        {
                cout << "    ";
        }
}